1. Field of the Invention
The invention concerns a security device for confidential information mentioned in a document. It also relates to a method for implementing such a device.
2. Description of the Related Art
A document can make it possible to communicate, in a confidential manner and to a given recipient, information such as for example an alphanumeric code. This type of document is encountered, for example, in the fields of banking, telecommunications, health, games and security. The application of the device of the invention is also envisaged in other fields where information circulates that is to be read by only a restricted number of people.
In order to ensure the confidentiality of the information while the document is circulating between the sender and the recipient, a device where confidential information is covered with a masking printing is known for example from FR-A-2 840 251, the information becoming readable by scratching off the masking printing. Depending on the masking printing, it may be possible, under certain lighting, to read the information without scratching off the masking printing. Additionally, excessive scratching may damage the printed information. There is then a risk of erroneous or impossible reading of at least part of the information. A masking element whose part covering the information is precut and does not adhere to the latter is also known through WO-A-99/24267. It suffices to remove this part in order to gain access to the information. By partially lifting the masking element at the level of the precut, it is possible to read the information. Additionally, it is possible to reposition this masking element after reading.
EP-A-1 293 359 describes a film on which information is printed. This film is stuck onto a document, at the level of a masking printing. The removal of the film, with the aid of a tab, causes defibration of the constituent material of the document, in this instance paper. With such a device, it is possible to unstick the film, read the information, reposition and restick the film without the defibration of the paper being visible.